Electrical connectors

ABSTRACT

An electrical connector comprises a body section provided with cantilever leg members extending outwardly from one side and in the same plane thereof, the free ends of the leg members having inturned and arcuate-shaped sections defining contacts for electrical engagement with conductive paths of a PC board. The leg members converge toward each other and they are provided with stabilizing lugs to maintain the contacts in position in their passageways of a dielectric housing.

United States Patent Kinkaid [151 3,656,093 [451 Apr. 11, 1972 [54]ELECTRICAL CONNECTORS [72] Inventor: Robert John Kinkaid, NewCumberland,

[73] Assignee: AMP Incorporated, Harrisburg, Pa. [22] Filed: Jan. 12,1970' [21] Appl. No.: 1,966

, Related 08. Application Data [63] Continuation of Ser. No. 653,419,July 14, 1967.

[52] [1.8. CL ..339/2l7S,339/17 L, 339/258 P, 339/276T [51] lnt.Cl..H0lr 13/12 [58] Field ofSearch ..339/217,258, 276

[56] References Cited UNITED STATES PATENTS 3,104,925 9/1963 Macnamara..339/217 3,123,428 3/1964 McKee ...339/256 2,682,040 6/1954 Batcheller..339/258 3,020,520 2/1962 Berg ..339/276X 3,031,640 4/1962 McKee..339/217 Primary Examiner-Richard E. Moore Attorney-Adrian J. LaRue 57ABSTRACT An electrical connector comprises a body section provided withcantilever leg members extending outwardly from one side and in the sameplane thereof, the free ends of the leg members having intumed andarcuate-shaped sections defining contacts for electrical engagement withconductive paths of a PC board. The leg members converge toward eachother and they are provided with stabilizing lugs to maintain thecontacts in position in their passageways of a dielectric hous-.

ing.

3 Claims, 10 Drawing Figures PATENTEDAPR 1 1 I972 SHEET 2 BF 2 Jill:

ELECTRICAL CONNECTORS This is a continuation of application Ser. No.653,419, filed July 14, 1967.

This invention relates to electrical connectors and more particularly toelectrical connectors for use in connection with panels such as, forexample, printed circuit boards.

In U.S. Pat. No. 3,075,167, a printed circuit connector is disclosedwhich includes parallel legs extending outwardly from a web portion in acantilever manner. The legs are disposed in a plane containing the webportion and the free ends of the legs are provided withinwardly-directed contact sections, also in the same plane as the legsand web portion. 'lhese contact sections are for engagement withconductive paths of a printed circuit board, but that they contain sharpedges which increases the wear on the conductive paths in addition tocausing abrasion to the paths if they are plated with precious metals.

U.S. Pat. No. 2,926,328 discloses a printed circuit connector whichcomprises parallel leg members extending outwardly from one end of abody portion at one side as opposed requires a lot of metal to make andthe legs are too flexible to provide positive contact. A similarconnector is described in U.S. Pat. No. 2,853,689.

An object of the present invention is to provide an electrical connectorwith cantilever legs provided with large area contact sections at thefree ends from thin-rolled stock.

Another object of the invention is the provision of an electricalconnector having stabilizing means to maintain the contact sections inposition in channels of a passageway of a housing.

A further object is to provide an electrical connector that has smoothcontoured contact surfaces for positive contact with mating contactsurfaces which reduces contact surface wear and increases contact life.

An additional object is the provision of an electrical connector havingcantilevered fork contacts with beams providing equal distribution ofcontact forces and torquing of the cantilever beams permitting thecontact areas to adjust to the surface configuration of the matingcontact surfaces.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich there are shown and described illustrative embodiments of theinvention; it is to be understood, however, that these embodiments arenot intended to be exhaustive nor limiting of the invention but aregiven for purposes of illustration in order that others skilled in theart may fully understand the invention and the principles thereof andthe manner of applying it in practical use so that they may modify it invarious forms, each as may be best suited to the conditions of aparticular use.

The invention is directed to an electrical connector which comprises aplanar body section having cantilever legs extending outwardly therefromand disposed in the same plane as the body section. Free ends of thelegs have contacts disposed substantially at right angles with respectto the plane of the legs and body section. The contacts have contactsurfaces at least three times the thickness of the legs and they arearcuateshaped in a fore-and-aft direction as well as in cross section.

In the drawings:

FIG. 1 is a perspective exploded, view of a dielectric housing I with apassageway in cross section and an electrical connector explodedtherefrom;

FIG. 2 is a cross-sectional view through a passageway of the housing ofFIG. 1 with an electrical connector in position therein;

FIG. 3 is a view taken along lines 3-3 of FIG. 2;

FIG. 4 is a view taken along lines 4-4 of FIG. 2 showing theconfiguration of the contact sections;

FIG. 5 is a side elevational view of an embodiment of the electricalconnector;

FIG. 6 is atop plan view ofFIG. 5;

FIG. 7 is an exploded plan view of a ferrule member and a wire to becrirnped therein;

FIG. 8 is a view similar to FIG. 7 with the wire crirnped in position inthe ferrule member;

FIG. 9 is a view taken along lines 9-9 of FIG. 8; and

FIG. 10 is a view taken along lines 10-10 of FIG. 9.

Turning now to the drawings and more particularly to FIGS. 1 through 4,a part of a dielectric housing H is illustrated which is provided withpassageways 11 for receiving electrical connectors EC. Passageways l arein communication with channel 2 in whicha printed circuit board is to bereceived. Each of passageways 1 includes projections 3 in opposingsurfaces and depressions 4 in other opposing surfaces.

Electrical connector EC comprises a contact section 5 and a ferrulesection 6. Contact section 5 includes a body portion 7 provided withextensions 8 along opposing sides thereof. An arcuate stop 9 is struckout from body portion 7 in about the central portion thereof. Stop 9 isdirected in the same direction as extensions 8. Extending outwardly fromthe front end of body portion 7 is a spring lance 10 which is bent backover body portion 7 in overlying relationship with respect to stop 9.Spring lance 10 has a wedge-shaped configuration as illustrated in FIG.2. Body portion 7 and extensions 8 fit snugly within the rear section ofpassageway l with extensions 8 engaging projections 3 in passageway 1 tolimit the movement of the electrical connector within the passageway andspring lance 10 seats in one of depressions 4 to limit movement of theelectrical connector out of the passageway. Arcuate stop 9 preventsspring lance 10 from being permanently set so as not to be operable.With depressions 4 being disposed in opposing surfaces of passageway l,the electrical connector can be inserted in the passageway in more thanone direction and still be operable.

Cantilever legs 11 extend outwardly from the front end of body portion 7and are disposed in the same plane containing body portion 7. As can bediscerned from FIG. 2, cantilever legs 11 are tapered inwardly towardeach other from body portion 7 toward the free ends thereof. The freeends of cantilever legs lll have arcuate-shaped sections 12 extending inthe same direction as extensions 8 which define contacts for electricalengagement with conductive paths of a printed circuit board. In crosssection as illustrated in FIG. 4, contacts 12 are radiused along eachside thereof in order to provide smooth surfaces therealong. Cantileverlegs 11 converge toward each other as illustrated in FIG. 2 so thatcontacts 12 extend within channel 2 and are spaced apart a distance toproperly engage the conductive paths of a printed circuit board.Stabilizing lugs 13 extend outwardly from the outer edges of legs 11rearwardly of contacts 12 and in the same direction as contacts 12 andextensions 8 to stabilize the movement of legs 11 in passageway 1 sothat contacts 12 will be free to move therein. As can be discerned fromFIG. 3, lugs 13 have a length slightly in excess of contacts 12in orderto properly guide contacts 12 within passageway 1 and the width ofcontacts 12 is in excess of three times the width of legs 11 whichprovides broad contacts with thin cantilever legs thereby permitting theuse of thin stock as opposed to stock the thickness of the width of thecontacts which would present numerous problems.

Recesses 14 are formed in body portion 7 and legs 111 to work-harden thematerial at these points to equalize pressure at the points of bendingof the cantilever legs. Contacts 12 provide smooth-contoured contactsurfaces for positive contact with the conductive paths of the printedcircuit board. The configuration of contacts 12 reduces wear on theconduc- 'tive paths and increases contact life. Contacts 12 aresusceptible to selected plating techniques to provide precious metalplating thereon instead of plating the entire connector. The arcuateconfiguration of contacts 12 provide an automatic printed circuit boardlead-in by virtue of the opposed arcuate configuration of the contacts.The contacts provide a broad contact area to distribute load forcesrequired for good contact. The broad contact area of the contacts alsosubstantially reduces insertion forces. The cantilever beams of the legsare susceptible to torquing thereby permitting contacts 12 to adjust andconform to the surface configuration of the conductive paths of theprinted circuit board.

Turning now to FIGS. 5 and 6, electrical connector ECa is illustratedwhich is an embodiment of electrical connector EC. Body portion 7 isprovided with a projection to permit the electrical connector to beforce-fitted into a passageway of a housing member with post 16extending outwardly from the rear surface of the housing and the ends ofbody portion 7' adjacent post 16 engaging the inner end of thepassageway to limit movement of the connector thereinto. Post 16 couldbe a ferrule section such as ferrule section 6. As can be discerned,cantilever legs 11' are provided with bent sections 17 along the area ofcontacts 12' so that contacts 12' are disposed centrally of cantileverlegs 1 1 to distribute the loading of the contacts on the conductivepaths of the printed circuit board about the center line of theelectrical connector.

FIGS. 7 through 10 illustrate ferrule section 6 of electrical connectorEC but of course this ferrule section can be used in conjunction withany other type of electrical connector in which electrical wire is to becrimped. Ferrule section 6 includes a wire-engaging portion 18 forcrimpably engaging the conductive portion of wire 19 and aninsulation-engaging portion 20 for engaging the insulation of wire 19 toprovide strain relief therebetween. Wire-engaging portion 18 is U-shapedin cross section and has chevron-shaped depressions or serrations 21formed therein. Serrations 21 permit the strands of wire or solid wireto be extruded thereinto upon crimping pressure being applied towire-engaging portion 18 thereby providing staggered interruptions inthe wire in an axial direction along wire-engaging portion 18 instead ofin planes normal to the axis of the wire-engaging portion in accordancewith conventional practice as illustrated in US. Pat. No. 2,800,638. Thecrimp performed by the chevron-shaped serrations does not thereforefatigue the metal and does increase the tensile to provide a moredesirable and effective crimp; corrosion resistance is improved andconductivity in the connection is more stable.

It will, therefore, be appreciated that the aforementioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiments of the invention, which are shown anddescribed herein, are intended as merely illustrative and not asrestrictive of the invention.

What is claimed is:

1. A stamped and formed electrical connector adapted for engagement witha printed circuit board or the like, said connector comprising:

a body portion having a pair of spaced-apart cantilever legs extendingfrom one end thereof, said body portion and said legs being stamped fromstrip stock material and lying along one plane,

said legs being formed inwardly and converging towards each other, saidlegs having contact means on their ends, said contact means comprisingarcuate formations on said legs extending normally of said plane of saidbody portion and said legs, said contact means providing opposed arcuatecontact surfaces which are spaced apart by a distance less than thewidth of said legs,

a pair of elongated embossments associated with each of said legs, eachof said embossments extending in the direction of its respective legpartially on its respective leg and partially on said body portion, thestock material of said legs being strengthened by work hardening in thevicinity of said embossments, and

retention lance means extending from said body portion between saidlegs, said retention lance means being reversely bent and extending oversaid body portion on the same side of said connector as the side of saidcontact means.

2. A connector as set forth in claim 1 including laterally extendingstabilizing flange means extending from the sides of said body portion,and laterally extending stabilizing ear means on said legs adjacent tosaid contact means, said stablitzing flange means and said stabilizingear means extending in the same direction as said contact means.

3. A stamped and formed electrical connector adapted for engagement witha printed circuit board or the like, said connector comprising:

a body portion having a pair of spaced-apart cantilever legs extendingfrom one end thereof, said body portion and said legs being stamped fromstrip stock material and lying along one plane,

said legs being formed inwardly and converging towards each other, saidlegs having contact means on their ends, said contact means comprisingarcuate fonnations on said legs extending normally of said plane of saidbody portion and said legs, said contact means providing opposed arcuatecontact surfaces which are spaced apart by a distance less than thewidth of said legs,

a work hardened zone associated with each of said legs,

each of said zones extending in the direction of its respective legpartially on its respective leg and partially on said body portion, thestock material of said legs being strengthened by work hardening in thevicinity of said zones and retention lance means extending from saidbody portion between said legs, said retention lance means beingreversely bent and extending over said body portion on the same side ofsaid connector as the side of said contact means.

1. A stamped and formed electrical connector adapted for engagement witha printed circuit board or the like, said connector comprising: a bodyportion having a pair of spaced-apart cantilever legs extending from oneend thereof, said body portion and said legs being stamped from stripstock material and lying along one plane, said legs being formedinwardly and converging towards each other, said legs having contactmeans on their ends, said contact means comprising arcuate formations onsaid legs extending normally of said plane of said body portion and saidlegs, said contact means providing opposed arcuate contact surfaceswhich are spaced apart by a distance less than the width of said legs, apair of elongated embossments associated with each of said legs, each ofsaid embossments extending in the direction of its respective legpartially on its respective leg and partially on said body portion, thestock material of said legs being strengthened by work hardening in thevicinity of said embossments, and retention lance means extending fromsaid body portion between said legs, said retention lance means beingreversely bent and extending over said body portion on the same side ofsaid connector as the side of said contact means.
 2. A connector as setforth in claim 1 including laterally extending stabilizing flange meansextending from the sides of said body portion, and laterally extendingstabilizing ear means on said legs adjacent to said contact means, saidstabilizing flange means and said stabilizing ear means extending in thesame direction as said contact means.
 3. A stamped and formed electricalconnector adapted for engagement with a printed circuit board or thelike, said connector comprising: a body portion having a pair ofspaced-apart cantilever legs extending from one end thereof, said bodyportion and said legs being stamped from strip stock material and lyingalong one plane, said legs being formed inwardly and converging towardseach other, said legs having contact means on their ends, said contactmeans comprising arcuate formations on said legs extending normally ofsaid plane of said body portion and said legs, said contact meansproviding opposed arcuate contact surfaces which are spaced apart by adistance less than the width of said legs, a work hardened zoneassociated with each of said legs, each of said zones extending in thedirection of its respective leg partially on its respective leg andpartially on said body portion, the stock material of said legs beingstrengthened by work hardening in the vicinity of said zones andretention lance means extending from said body portion between saidlegs, said retention lance means being reversely bent and extending oversaid body portion on the same side of said connector as the side of saidcontact means.